Safety plug



AJune 3, 1930. R, H KYLE 1,762,064

SAFETY PLUG Filed March 25, 1929 l' r.1111111nlrv 71111111111111111111. '111114 A ,"wx

ffl'. y j r Patented June 3, 1930 PATENT ori-ICE ROBERT H. KYLE, OIF GRANDVIEW, CALIFORNIA SAFETY PLUG l Application led March 25, 1929. Serial No. 349,863.

This invention relates to an electric appliance plug, the general object of theinvention being to provide means for breaking the circuit in the plug when the appliance be- 5 comes heated to an excessive degree, thereby preventing damage to the appliance 'and a possible fire, due to the excessive heat ofthe applince igniting the support on which it 1s lace 0 p Another object of the invention is to so construct the parts that thel lug can be easily restored to normal con 'tion after the circuit has been broken and to make the circuit breaking means adjustable so that the circuit can be broken at any desired temperature.

This invention also consists in certain other features of construction and ,in the com- -bination and arrangement of the several parts, to be hereinafter fully described, illustrated in the accompanying drawings and specifically pointed out in the appended claim.

In describing the invention in detail, ref` erence will be had to the accompanying .drawings wherein like characters denote likeor corresponding parts throughout the several views, and in which Figure 1 is a sectional view through the im roved plug.

Figure 2 is a planview, with one of the sections of the plug removed.

Figure 3 is a view similar to Figure 1, but' showing the parts in circult breaking position.

In these views, the numeral 1 indlcates the usual sectional casing of an appliance plug, this casing containing the pair of terminals 2 for receiving the terminal posts of an electrical appliance, such as an iron, toaster or the like. One of the-conductors 3 is connectf ed with one of the terminals 2 in the ordinary manner, but the other conductor 4 is connected with a lever 5, the pivot pin 6 of which is carried by the bracket 7 located in the casing. A spring 8 is arranged on the pin andv bears against the lever and tends t o hold the same in spaced relation to the termlnal 2 over which the lever extends. A sleeve 9 1s threaded to one of the sections of the casing and if desired or necessary, a reinforcing piece may be placed in the section to receive this sleeve. l

A button 10 passes through a hole in the section into the sleeve and is connected with the sleeve by fusible material 11, this button being so arranged that it will hold the lever against the terminal so that current will pass through the lever into the terminal and thus pass to the appliance. This position of the parts is shown in Figure 1.

When the appliance is heated to an excessive degree, the heat transmitted to the button from the lever will fuse the material 11 so that the button will be pushed upwardly by the spring actuated lever and thus the lever will move away from the terminal and break the circuit to the appliance. As soon Y as the fusible material cools, it will hold the button in its new position so that it is simply necessary to reverse theV sleeve and button to restore the appliance to its normal position with the lever contacting the terminal.

From the foregoing it will be seen that the device automatically breaks the circuit of the appliance when the same becomes excessively heated, thus preventing damage to the appliance by possible fire.

The degree of heat at which the circuit breaking means will come into operation can be regulated by varying the composition of the fusible material, the thermic conductivity of the lever and button, the area of contact between the button and lever and the ventilation of the plug. Y

It is thought from the foregoing description that the advantages and novel features of the invention will be readily apparent.

' It is to be understood that changes may be made in the construction and in the combination and arrangement of the several parts, provided that such changes fall within the scope of the appended claim.

What I claim is .A safety plug of the class described comprising a casing, a pair of terminals therein, a lever pivoted in thecasing and arranged to contact one of the terminals, a spring for normally holdin the lever outV of Contact with the termina fusible means for holding the lever in contact with'the terminal, a conductor connected 'with one terminal a oon-v ductor connected with the lever, said fusible means comprising a sleeve threaded in the casing, a button passing throu h the sleeve and engaging the lever to ho d the same against the terminal, fusible material between the button and sleeve for holdin the button against movement, said sleeve an button being reversible whereby they can be reversed, after the material has been fused and cooled to enable the parts to be again ustd for holding the lever against the termina In testimony whereof I alix my si ature.

ROBERT H. K E. 

